Hyperopia develops in children because children are born with a shorter eye axis than adults (i.e., hyperopia is formed by a short eye axis). The anterior-posterior diameter of the eye at birth is only 16 mm, much smaller than the 24 mm of adults. The eye grows fastest in the first few years, gradually developing into a sphere. By the age of 4 to 5 years, the speed of eye development starts to decrease, and at this time it can approach 22 mm. Normally, the eye axis develops slowly to the length of an adult only by the age of ten to eighteen, so children should have varying degrees of hyperopia under normal circumstances until the age of ten (the vast majority are below three hundred degrees). Children before the age of ten have mild hyperopia, which is a physiological (normal) phenomenon. The growth rate of each part of the eye is also disproportionate at various times, with the posterior part of the eye growing faster than the anterior part. Light is converged by the refractive system of the adult 24 mm eye axis and is imaged just above the retina, so light is converged by the refractive system of the newborn child’s 16 mm eye axis and is imaged behind the retina, so a short eye axis naturally leads to hyperopia. The younger the child, the shorter the eye axis, and the higher the corresponding farsightedness. However, hyperopia has a great characteristic: the degree will gradually decrease with age, physical development, and the lengthening of the eye axis, until the length of the eye axis is close to the adult level, and the degree of hyperopia is close to orthopia (no degree), and when the development of the anterior and posterior axes of the eye is completed, it becomes orthopia. This process is called orthokeratology, and every normal eye undergoes this “orthokeratology” process. If the axis of the eye is too long due to overdevelopment, the eye will go beyond orthophoria to myopia. Therefore, when the farsightedness is below 75 degrees, it is important to pay attention to the prevention of myopia in order to prevent the excessive growth of the eye axis to form myopia.